PT - JOURNAL ARTICLE AU - Parisa Kakanj AU - Sabine A. Eming AU - Linda Partridge AU - Maria Leptin TI - Long-term <em>in vivo</em> imaging of <em>Drosophila</em> larvae AID - 10.1101/744383 DP - 2019 Jan 01 TA - bioRxiv PG - 744383 4099 - http://biorxiv.org/content/early/2019/08/24/744383.short 4100 - http://biorxiv.org/content/early/2019/08/24/744383.full AB - The Drosophila larva has been used to investigate many processes in cell biology, including morphogenesis, physiology, responses to drugs and new therapeutic compounds. Despite its enormous potential as a model system, it has technical limitations in cases where longer-term live imaging is necessary, because of the lack of efficient methods for immobilising larvae for extended periods. We describe here a simple procedure for anaesthetisation and long-term in vivo imaging of the epidermis and other larval organs including gut, imaginal discs, neurons, fat body, tracheae and haemocytes, and show a procedure for probing cell properties by laser ablation. We include a survey of different anaesthetics, showing that short exposure to diethyl ether is the most effective for long-term immobilisation of larvae. This method does not require specific expertise beyond basic Drosophila genetics and husbandry, and confocal microscopy. It enables high-resolution studies of many systemic and sub-cellular processes in larvae.